Wireless signaling system



Witnesses July 15, 1924. 1,501,664

A. HUND WIRELESS S IGNALING SYSTEM Filed Sept 18. 1914- His Attorneg.

Patented July 15, 1924.

UNITED STATES AUGUST QHUND, OF SCHENECTADY, NEW YORK, ASSIGNO'R T0COMPANY, A CORPORATION or new YORK.

GENEEAL saws-m WIRELESS SIGNALING SYSTEM.

Application filed September 18, 1914.

To all whom it may concern:

Be it known that I, AUGUST HUND, a sub ject of the Emperor of Germany,residing at Schenectady, county of Schenectady, State of New York, haveinvented certain new and useful Improvements in \Vireless SignalingSystems, of which the following is a specification.

My present invention relates to wireless signaling systems and moreespecially to the wireless transmission of speech or other sound waves,such, for example, as those produced by musical instruments.

It has heretofore been proposed to connect a source of continuous highfrequency oscillations to an antenna and to modify the waves sent out inaccordance with the signals to be transmitted without interrupting theircontinuity. U. S. Patents #706,747 and 7 53,863 to Fessenden describesystems of this character. Difliculty has been ,experienced, however, inthe practical operation of such systems in providing suitable apparatusfor controlling a sufficient amount of energy and for producing largeenough energy variations in the transmitted waves to reproduce the soundwaves at a distant point.

The object ofmy invention is to overcome this difficulty by providing anorganization which will produce continuous waves which are capable ofradiating large amounts of energy and which have a large variation inamplitude in accordance with the signals to be transmitted and at thesame time provide a system which is easy of adjustment and which issimple and eflicientin itsoperation.

In carrying my invention into efiect Iconnect a source of high frequencyoscillations to an antenna and also connect to suitable points in theantenna circuit an energy consuming device which ,willabsorb more orless energy from the antenna in accordance with the signals to betransmitted. The device which I prefer to use for this purpose is onewhich is especially. adapted for use with high voltages andcomparatively small currents. It is a well known fact thatwith aproperly tuned antenna to which is connected a source of high frequencyoscillations there exists,

because of certain resonance phenomena, a large difference ofpotentialbetween-different points in .the antenna circuit. vByconnecting an energy consuming device of the preferred type in parallelWltllthe antenna which Fig.

former 3 to .tential between the Serial No. 862,325.

circuit between two points between which there is a large difference ofpotential and by suitably varying the amount of energy consumed by saiddevice it is possible to vary the amount of energy which will beradiated by the antenna, the larger the amount of energy consumed bythis device the smaller will be the amount radiated.

The novel features of my invention are pointed out with particularity inthe appended claims. The invention itself, however, will best beunderstood by reference to the following description taken in connectionwith the accompanying drawing in l illustrates diagrammatically one wayof carrying my invention into effect and Fig. 2 shows a modification.

Asshown in the drawing the antenna 1 is grounded as usual andhasconnected thereto a source of high frequency oscillations which inthis case consists of the high frequency alternator 2. This may beinductively connected to theantennaby means of frequency is placed inseries with the antenna. In some cases itmay be desirable to connectthesource of energy to the antenna by loosely coupling the primary oftransthis inductance. Ifthe antenna is comparatively smallthe valueofthis inductance required to givethe proper tuning will becorrespondingly large and as aresult .there will be a large differenceof poterminals ofthe inductance. The terminals of this inductance may beconnected directly tothe anodes-50f an electrondischarge relay 6 whilethe mid dle point of the inductance is connected {to the cathode 7 ofthe relay. These electrodes are enclosed in an envelope exhausted tosuch a high degree that when highpotentials are impressed upontheelectrodes the flow of currentbetween the electrodes is not .ac

companied by any visible.manifestationof gas ionization. lVhile thecurrent which will flow through a relay of this type is 'limited thevoltage which may be employed is practically unlimited except bydifficultiesof insulation. The cathode 7 is. of filamentary form and isprovided with a battery ,8,or

other suitable means for heating. A consurrounds the cathode 7.

ducting body ,9' in the form of a grid also With the arrangement thusfar described it will be seen that when energy is supplied to theantenna there is a high potential impressed upon the electrodes of therelay 6. Hence there will be a flow of current from the cathode 7 to theanodes During onehalf wave of the oscillation current will flo W to oneof the anodes and during the next half wave current will flow to theother anode. As a result there will be a continual consumption of energyin the device. If now a positive potential be impressed upon the gridthe flow of current will be increased while if a negative potential isimpressed on the grid the flow of current will decrease. Hence byvarying the grid potential the amount of energy consumed by the relaymay be varied as desired and as a result the amplitude of the currentwave and the amount of energy radiated by the antenna may be variedaccordingly. If it is desired to transmit speech or other sound wavesthe grid potential may be varied in accordance with potential variationsproduced by a telephone transmitter 10. The transmitter is provided withthe usual battery 11 and is preferably connected to the grid 9 throughthe transformer 12 as indicated, one terminal of the transformer beingconnected to the grid through the potentiometer 13 while the otherterminal is connected to the cathode. In order to secure the bestresults it will usually be found desirable to impress an extra potentialupon the grid 9 in addi tion to that produced by the transformer 12.This extra potential may be derived from a battery 14. and may be giventhe proper value by adjusting the potentiometer 18. In order to increasethe amount of energy which may be consumed withoutoverheating the relay6 it may be desirable to insert series resistances 15 as indicated.

Vhile I have described only one way in which my invention may be carriedinto effect it will be apparent to one skilled in the art that manymodifications thereof may be made without departing from the scope ofthe appended claims. The essential thing required in practicing myinvention is the selection of two points in the antenna circuit betweenwhich large difference of potential exists. In case the antenna itselfpossesses such a high inductance that but little tuning inductance isrequired one of these points may be found in the antenna itself and itmay be desirable to connect one electrode of the electron dischargerelay to the extreme end of the antenna. Also while I have illustratedand described an organization in which energy is abstracted from bothhalf waves 1 have found in actual practice that speech may beefficiently transmitted when the connections are so modified that energyis absorbed from only one-half wave of current. This may be done bymerely connecting the cathode to one terminal of the induc- 1 tance andconnecting the two anodes in parallel to the other terminal as indicatedin Fig. 2.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is 1. The combination in a wireless signaling system of anantenna, a source of energy con-- nected to said antenna, a tuninginductance in series with said antenna, a relay comprising a pluralityof electrodes enclosed in a highly evacuated envelope, direct electricalconnections from said electrodes to points in said inductance betweenwhich there is a lar e difference of potential and means cooperatingwith said relay whereby the ampli tude of the current flow in saidantenna may be varied in accordance with the signals to be transmitted.

2. The combination. in a wireless signaling system of an antenna, a highfrequency source of energy connected to said antenna, a tuninginductance in series with said antenna, .an electron discharge relayhaving a plurality of, electrodes, direct electrical con nections fromsaid electrodes to points in the inductance between which there is alarge difference of potential, and means for varying the current throughsaid relay in accordance with the signals to be transmitted, therebyproducing a similar variation in the amplitude of the current flowing inthe antenna.

8. The combination in a wireless signaling system of an antenna, asource of energ connected to said antenna, a relay comprising a cathodeand two anodes enclosed in a highly exhausted envelope, a tuninginductance in series with said antenna, electrical connections betweensaid anodes and the terminals of said inductance, an electricalconnection between said cathode and an in-- termediate point in saidinductance. a. conducting grid surrounding said cathode and means forvarying the potential of said grid in accordance with the signals to betransmitted to produce a similar variation in the amplitude of thecurrent flow in the antenna.

4. The combinationin a wireless signaling system of an antenna, a highfrequency source of energy connected to said antenna, a tuninginductance in series with said antenna, means for diverting a variableamount of energy from said antenna comprising an energy consuming devicehaving a plurality of electrodes, direct electrical connections fromsaid electrodes to points in the inductance between which there is alarge difference of potential, a conducting grid surrounding one of saidelectrodes and means for varying the potential of said grid inaccordance with the signals to be transmitted to produce a variation inthe amplitude of the current flow in the antenna.

5. The combination in a wireless signaling system of an antenna, a highfrequency source of energy connected to said antenna, means fordiverting a variable amount of energy from said antenna comprising arelay having a plurality of electrodes enclosed in a highly evacuatedenvelope, a tuning inductance in series with said antenna, directelectrical connections between said electrodes and points in saidinductance between which there is a large difference of potential, aconducting grid surrounding one of said electrodes, a telephonetransmitter and means for varying the potential of said grid inaccordance with variations in current through the telephone transmitterto produce a variation in the amount of energy directed from saidantenna.

6. The combination in a wireless signaling system of an antenna, a highfrequency source of energy connected to said antenna,

means for diverting a Variable amount of energy from said antenna inorder to vary the amplitude of the current flowing therein, said energydiverting means comprising a relay device having an anode, an electronemitting cathode and a current controlling grid enclosed in a highlyexhausted receptacle, a tuning inductance in series with said antenna,direct electrical connections between the anode and cathode of saidrelay device and points in the inductance between which there is a largedifference of potential, and means for varying the potential of thecurrent controlling grid in accordance with the signals to betransmitted.

In witness whereof, I have hereunto set my hand this 17th day ofSeptember, 1914.

AUGUST HUN D. Witnesses:

BENJAMIN B. HULL, BENJ. H. WEISBROD.

